The present invention is directed toward an apparatus and method for retaining a first circuit board on a second circuit board such as a motherboard.
Computer systems often include a plurality of integrated circuit boards capable of performing different functions when interconnected to one another. Such an arrangement provides advantages of enhanced standardization of parts as well as increased varieties of possible computer systems. For instance, using the same basic hardware, many variations of a computer system may be created by including or not including various functionally distinct circuit boards with components based on the circuit boards. Additionally, circuit boards with computer components may be replaced with more capable circuit boards as such devices are developed.
A typical arrangement for a computer system is to have a backplane circuit board, such as a motherboard, that serves as a platform on which the computer system may be built. The motherboard typically has a number of sockets or slots into which other circuit boards with components may be plugged to form electrical and mechanical connections between the circuit boards and the motherboard. Examples of circuit boards with components that may be plugged into the motherboard include one or more central processing units, main memory cards, video adapter cards, video acceleration cards, sound cards, SCSI controller cards, parallel or serial interface cards, game adapter cards, network cards, and others. Circuit boards with components such as these may plug into a motherboard through connectors along one edge of the circuit board. The edge connectors plug directly into a slot or socket. When attached in this manner, the circuit board may be substantially perpendicular to the motherboard.
While it is convenient to have circuit boards with components that may be added to or removed from a motherboard so easily, significant problems are created if the circuit boards become electrically disconnected from the motherboard. Maintenance of a secure electrical connection can be assured by an adequate mechanical connection. Mechanical and subsequent electrical disconnection may occur when a computer system is subjected to jarring loads like those present during shipping. Therefore, significant design efforts have been directed toward adequate mechanical connection between socket connected circuit boards and the motherboard.
One connection that has been of particular concern is the connection between the central processing unit, or processor, and the motherboard. Such a processor is often resident on a circuit board. The circuit board and processor together will be referred to below as a processor package. The Intel Corporation P6-based processor packages connect to the motherboard through what is known as Slot 1 or Slot 2 connectors. A Slot 1, or 242-contact slot connector, is used with PENTIUM II, PENTIUM III, or CELERON processor packages and is shown in FIG. 1 as connector 104. The Slot 2, or 330-contact slot connector, is used with Xeon processor packages. However, Slot 1 and Slot 2 electrical connectors are not adequate to secure a processor package to a motherboard under normal service loads. Therefore, mechanical retaining structures must be added around a Slot 1 or Slot 2 connector to secure the processor package to the motherboard. A typical mechanical retaining structure is known as a xe2x80x9cgoal postxe2x80x9d because it physically resembles a football goal post with two vertical uprights. See FIG. 1 illustrating goal post 100 and uprights 102. Each of the vertical uprights is positioned to support a vertical edge of a processor package that may be supported in connector 104. Support along the vertical edges, however, has not proven adequate to support the processor package. A PENTIUM II or PENTIUM III processor package is illustrated in FIG. 2 and a CELERON processor package is illustrated in FIG. 3.
To adequately support various Slot 1 and Slot 2 processor packages, a number of specialized retaining structures have been developed. For instance, U.S. Pat. Nos. 5,726,865 and 5,642,263 disclose such structures. A problem with both of these structures, however, is that they are not capable of functioning with each of the standard Slot 1 or Slot 2 processor packages. Additionally, the ""865 patent requires special cutouts in the circuit board of the processor package. The ""263 patent provides a top cover that gives additional retaining strength, but a single apparatus could not be used for processor packages of varying heights. Unfortunately, standard processor packages come in different heights. For instance, a standard CELERON processor package is significantly taller than a standard PENTIUM III processor package. See FIGS. 2 and 3. Therefore, separate retaining apparatuses would be required for each different processor package under the ""263 patent.
Another shortcoming is that the structure of the ""263 patent is not designed to exert a downward biasing force on the processor package. Although the ""263 patent would prevent a processor package from moving beyond the cover, a more optimal solution would create a downward biasing force on the processor package. Such a downward force would reduce the movement of the processor package in the connector, and consequently, would reduce wear on the connections between the processor package and the connector that could otherwise occur.
Goal post connectors capable of excepting both a standard CELERON processor package and a standard PENTIUM III processor package are currently commercially available. One such connector is Part No. PT11008-5301 made by FOXCONN Electronics, whose parent company is Hon Hai Precision Ind. Co., LTD., Taipei, Taiwan, R.O.C. As illustrated in FIG. 1, the FOXCONN type connector 100 provides holes 101 and 103 in both uprights 102. Holes 101 and 103 are for aligning with tabs 201 of a typical PENTIUM II or PENTIUM III processor package 200 as shown in FIG. 2. Two pairs of holes 101 and 103 are provided so that the processor 200 may face in either direction relative to the connector 100 (FIG. 1). For the CELERON processor package 300 shown in FIG. 3, the tabs 301 fit beneath the wings 105 or the wings 107 of the upright 102 as shown in FIG. 1. Two pairs of wings 105 and 107 are provided so that the processor 300 may face in either direction relative to the connector 100. Although the FOXCONN connector provides support for more than one variety of processor and does not require custom alterations to a processor, it alone does not provide adequate support under many observed service conditions.
An improved system would combine the flexibility and interchangability of a standardized goal post connector with the security and strength of a customized connector and processor. Further, the improved system would apply a biasing force to a processor package, or other circuit board, to further secure the device to a connector and its associated second circuit board. Additionally, an improved device would allow for a part to be merely added to an existing goal post type connector or similar structure. An improved device would also be easy to install and remove, requiring no tools or special skills to accomplish either task.
An embodiment of the invention is a clip for securing a first circuit board to a second circuit board. The clip is coupled to a first upright and a second upright. The uprights are coupled to a second circuit board. Therefore, by connection of the clip to the uprights, the first circuit board is secured relative to the second circuit board. The clip includes a first end for coupling to the first upright and an interior member coupled to the first end. A portion of the interior member contacts the first circuit board and biases the first circuit board toward the second circuit board. The clip also includes a second end coupled to the interior member. The second end is for coupling to the second upright.
Another embodiment of the invention is a computer system with a first circuit board and a first upright and a second upright engaged with the first circuit board to support the first circuit board. The computer system also has a second circuit board coupled to the first circuit board. The second circuit board is coupled to the uprights as well. The computer system has a memory module coupled to the second circuit board and a power supply electrically connected to the second circuit board. The computer system also has a clip to secure the first circuit board relative to the second circuit board. The clip includes a first end coupled to the first upright and an interior member coupled to the first end wherein a portion of the interior member contacts the first circuit board and biases the first circuit board toward the second circuit board. A second end of the clip is coupled to the interior member and is coupled to the second upright.
Still another embodiment of the invention is a method of securing a first circuit board to a second circuit board. The method includes the acts of coupling the first circuit board to a slot connector on the second circuit board. By this connection, two opposite edges of the first circuit board are supported by two uprights at the two opposite edges. The two uprights are coupled to the second circuit board. Another act of the method is attaching a clip between the two uprights such that a portion of the clip contacts the first circuit board and biases the first circuit board toward the second circuit board.